Extruder Steps per mm Calibration with or without hotend?

Hi Guys

Wondering what peoples takes on this are.

When you calibrate your steps per mm for your extruder, iv seen examples were some people calibrate with the hotend off and some calibrate with the hotend connected and at there desired temps.

Now last time i calibrated i thought well the true steps per mm are correct with no hotend, and if they then differ your hotend is not hot enough. but this then leads to running filament hotter iv found.

what do you guys do when calibrating? Also if you do go with hotend on i take it you have different steps per mm for different materials used

hot end at temp for z axis calibration. thermal expansion changed debth along z.

not talking about Z Stop

Im on about Extruder calibration steps per mm.

Do it while extruding at speeds you expect while printing. Then there is no question. In general, calibrate in conditions as close as possible to real operating conditions.

You might try at speeds above and below normal extrusion speeds too, just to make sure there is no slipping.

Ideally you should get the same results with or without the hot end. It is, after all, a measure of the filament going IN to the extruder, not coming out of the hot end.

I usually measure with the hot end in place simply because it's a PITA to remove.

What might be a good thing is to calibrate without the hot end, then put the hot end back on and bring it up to temperature. Then try extruding. Do it slowly so you don't exceed the speed limit of the hot end. If the numbers are not equal, you are seeing slippage.